There are many different analyses of the Green Children story, ranging from an interpretation in which the characters are fictional, and the green children represent the ancient Briton communities that disappeared after the Norman Conquest, to a more prosaic one in which the children are Flemish immigrants suffering from either arsenic poisoning or malnutrition. (There are off-the-wall interpretations as well: the children have arisen from the underworld, they're actually extra terrestrials, etc.) I have no idea where the children came from, why they didn't speak English (although that Flemish story has a ring of truth to it), but I have a guess about their skin coloring. My guess, informed by Marvin Harris and Eric B. Ross's Food and Evolution: Toward a Theory of Human Food Habits, is that they weren't green when they were found, but they turned green, accidentally poisoned by the very people who were trying to save them.
For, as the stories all confirm, the first and only food the children would accept was beans, and in the 12th Century, the beans that would be in England would be fava beans, and fava beans, well, they can be poison.
Favism is a disease that only appears in people who have inherited the X-linked deficiency in enzyme glucose-6-phosphate dehydrogenase (G6PD). People who have a deficiency in G6PD have bodies that prematurely destroy their red blood cells when exposed to certain triggers; for some people with this deficiency, fava beans and fava pollen act as triggers. Exposure to fava leads to hemolysis, which if unchecked, leads to severe jaundice and eventual organ failure. This disease, favism, appears most frequently (thought not solely) in people of Asian, Mediterranean, or African descent, and the symptoms tend to be most devastating to males.
So, the kids may not have been a vibrant green, but a much more sickly yellow-y green. And the girl, likely less affected, acclimated and began a diet less concentrated in deadly triggers. But the boy, more affected, never recovered, and died.
Pythagoras is a shady figure. The 6th Century BC Greek philosopher led a sect based on secret knowledge in southern Italy, and though, as I mentioned, the society was secret, many of his tenants were written down well after his death, leading, of course, to further confuse what may have already been muddy or muddy what may have once been clear.
One of his more unusual teachings was simple-sounding: don't touch fava beans. Some theorize he made this rule because he believed fava beans were made of the same material as humankind; thus, if the nitrogen nodules on the roots were cut, they would bleed, just as our veins would bleed. I pulled up a fava bean, shook the soil off the roots to expose the nitrogen nodules, and cut one open, just to see if it even turned red or had any reaction. Nope. Creamy white. Nothing blood-colored. Others argue he preached avoiding beans because they looked like testicles, and really, he was demanding abstinence. Indirectly according to these people, he had already tripped upon the future euphemism, "frank and beans."
There is another story that, in many sources, follows him about fava beans and several of his disciples; while being attacked by Cylon (Cylon? Those cylons are always tricky!), a Croton nobleman who rejected some of Pythagoras and his followers' political maneuvers, these disciples refused to run through the blooming fava field when trying to escape. They refused to touch the beans. They had the choice to escape to life through the field or to be outnumbered and die, and they held to the edict so powerfully they chose death over breaking it.
But, if Pythagoras's theory was not based on either an aversion to sex or an aversion to eating anything somehow seemingly meaty, and instead on an early understanding of favism, maybe the choice wasn't between life through the field or death at the sword. Maybe either choice meant the possibility of death.
The fava bean I grow in my garden is the Crimson Flowered fava, a very old variety with its own (near) death tale. I love it for its beauty and its small stature, the sweet way its flowers smell and its jewel green seeds. But I also love it because, with a backstory so dark, it is fitting that these favas have flowers that are blood red.